How to Create Custom entity in Big commerce stores screen?

I’m 2 months late, but in case anyone else stumbles across this you actually wouldn’t need to add it to that class specifically you can just implement the IProcessorsFactory interface and set the ConnectorType to “BCC”(BCConnector.TYPE).

Short explanation is that the system registers all instances of that interface and then effectively merges the ProcessorTypes that are returned based on the ConnectorType.

public class MyBCProcessorsFactory : IProcessorsFactory
{
    public string ConnectorType => BCConnector.TYPE;

    public IEnumerable<KeyValuePair<Type, int>> GetProcessorTypes()
    {
        yield return new KeyValuePair<Type, int>(typeof(MyCustomProcessor), 160);
    }
}